Genetically identical twins – but not so identical traits

Genetically identical twins – but not so identical traits

Identical twins with different skin, hair and eye colors – Gene sequences don’t determine traits

Excerpt: “Two baby girls from County Durham are thought to be the first genetically identical twins in the UK to be born with different eye and skin colour.

Before their birth, placental sampling had shown the twins were monozygotic – they had developed from the same fertilised egg and share the same DNA sequence.
‘Alternatively, sometimes markers on the DNA which influence the extent to which the DNA is expressed can be different in the twins. We do have some evidence that skin colour is subject to this kind of “epigenetic'” control,’ Dr Steves added.”
(April 19, 2017)

Excerpt: “Although identical twins have the same genes as each other, their epigenomes — the collection of methyl marks studding their DNA — are different by the time they reach adulthood due in part to environmental factors. Reprogramming the skin cells of adult identical twins to their embryonic state eliminated most of these differences, the researchers found when they studied cells from three sets of twins. However, there were still key epigenetic differences between twins in terms of how the iPSCs compared to ESCs.

“In the past, researchers had found lots of sites with variations in methylation status, but it was hard to figure out which of those sites had variation due to genetics,” says Panopoulos. “Here, we could focus more specifically on the sites we know have nothing to do with genetics.” That new focus, she says, is what allowed them to home in on the MYC binding sites.”

My comment: Human skin, hair or eye colors are not determined by gene sequences. Instead, traits are determined by epigenetic control of gene expression. Some of the epigenetic markers can be very stable. Histone methylation marks can be passed on for at least 14 generations according to a new study:

These findings destroy pseudoscientific claims about mutations made by population genetics. There is no such a thing as a human race. We are all the same, human beings, created by God.

Scientists should place these facts in the context of ecological adaptation and variation within kinds. There are no mechanisms for large scale evolution. Don’t get lost.

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